1. Technical Field
The present invention generally relates to methods and compositions for the treatment of herpes simplex virus and, in particular, to a method and composition for topical treatment of active phase lesions resulting from recurrent viral infection caused by herpes simplex virus.
2. Background of the Invention
Recurrent viral infection by herpes simplex virus, also known as Herpesvirus Hominis, is characterized by lesions which may appear anywhere on the skin or mucosa. Eventually, the lesion base inflames and develops clusters of small fluid-filled vesicles. Without treatment, the vesicles and lesions will resolve in several days to dry scabs. There are two known strains of herpes simplex virus (HSV), namely, HSV-1, commonly causing herpes labialis and keratitis, and HSV-2, which is usually genital herpes.
Treatment of herpes lesions often includes application of topical agents such as idoxuridine, trifluorothymidine, or acyclovir. In addition, prior art patents also disclose various compositions and methods for topical treatment of symptoms of herpes simplex virus which may include use of anti-viral agents, such as benzalkonium chloride, e.g., U.S. Pat. Nos. 4,283,421, 4,585,656, 4,661,354, 4,760,079, 4,803,224 and 4,797,420. None of these compositions, however, employ the combination of treatment agents disclosed herein.
According to the present invention, a method and composition has been developed for improved topical treatment of active phase lesions resulting from recurrent infection by herpes simplex virus. The present invention includes the use of two primary agents, namely, an aqueous solution of a benzalkonium halide, preferably benzalkonium chloride, and a dry form of the herb Echinacea purpurea, preferably in powder form. In practicing the method of the present invention, an active phase herpes lesion is first thoroughly wetted by spraying or dabbing the benzalkonium chloride solution onto the surface of the lesion. Next, the wetted surface of the lesion is dusted with the powder form of Echinacea purpurea to create a coating. The coating must be maintained throughout treatment until the lesion is resolved. Hence, it is preferred that periodically the coating of Echinacea purpurea powder be replenished through additional dusting of the lesion surface.
As an alternative to the above method, the present invention also discloses the saturation of a powder form of Echinacea purpurea with benzalkonium chloride to create a paste. The paste is applied to cover the lesion surface and, thereby, form a coating. Again, the coating must be maintained during treatment. Frequent replenishment of the coating by reapplication of the paste may, however, be required. The coating is maintained until the active phase of the lesion is resolved.
The present invention can also be practiced by using other alternative methods. For example, the benzalkonium halide and Echinacea purpurea composition can be formulated as a liquid, powder, gel, ointment, or any form of such composition as appropriate for topical application. Regardless of the form of the topical composition, the present invention is applied and reapplied to maintain a coating on the afflicted surface.
Preliminary clinical testing on human subjects for both HSV-1 and HSV-2 strains of herpes simplex virus reveals an unexpected and surprising rapid resolution of the active phase lesions, often within twenty-four hours of treatment initiation. In addition, after treatment, there appeared to be longer latency periods between recurrence of the active phases than had been observed prior to topical treatment with the present invention.
Other advantages and aspects of the invention will become apparent upon making reference to the specification and claims.
While this invention is susceptible of embodiment in many different forms, there will herein be described in detail a preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the illustrated embodiment.
The present invention discloses the use of benzalkonium halide, such as benzalkonium bromide, but preferably benzalkonium chloride, as an anti-viral wetting agent which is used in combination with a dried form of a herbaceous plant from the genus Echinacea and, in particular, Echinacea purpurea. 
As used in the present invention, benzalkonium chloride is an aqueous solution formed by a 1 part mixture of n-alkyl dimethyl benzyl ammonium chlorides and 750 parts water, preferably sterile water. Benzalkonium chloride in this form is commercially available under the trademark ZEPHIRAN(copyright), and has been known as an anti-infective and anti-viral agent with a moderately long duration period of therapeutic action.
Echinacea purpurea is a species of a herbaceous plant of the genera Echinacea, which is one of three genera of the family Asteraceae. Echinacea purpurea has a long reported use for its therapeutic and medicinal effects and is commercially available in dry powder form. Some of these reported uses include topical treatment of snake bites, infected wounds, and intra-oral treatment of a sore throat.
In one form of the present invention, benzalkonium chloride is used to wet the surface of an active phase lesion of herpes simplex virus. Then, Echinacea purpurea, in dry powder form, is dusted onto the wetted surface of the lesion until a coating is formed on the lesion surface. For the duration of topical treatment, usually about twenty-four hours, the Echinacea purpurea coating must be maintained. Therefore, periodic replenishment of the coating by additional dusting of the lesion surface is often required.
In another embodiment of the composition of the present invention, Echinacea purpurea powder is wetted until saturated with benzalkonium chloride to form a paste. The wetted paste form of Echinacea purpurea powder is then applied and adheres to the surface of the lesion. Again, frequent replenishment of the paste in order to maintain a coating on the surface of the lesion is required for the duration of topical treatment.
In other embodiments of the composition of the present invention, the dry form of Echinacea purpurea can be combined with the benzalkonium halide into various forms that can be applied topically. For example, the Echinacea purpurea can be combined with the benzalkonium halide to form a liquid, powder, gel, ointment or any form of such composition as appropriate for topical application. These forms of the present invention are also applied to an area having the active phase of herpes simplex virus to coat the area. The treated area is periodically retreated with the topical composition throughout duration of the treatment to maintain the coating. In the liquid, powder, gel and ointment forms, an additional suitable carrier may be added to the composition. For example, a carrier may be added to maintain the composition in a gel form. In the powder form, the benzalkonium halide is used in its dry form and not mixed with water to form a solution.
Surprisingly, the components of this mixture cooperate to give a therapeutic effect and enhanced antiviral activity not suggested by the known properties of benzalkonium chloride and Echinacea purpurea. No clear explanation of this unexpected cooperative action has been discovered, although it is postulated that the combination releases an enzyme from Echinacea or produces another by-product which alters or causes a degeneration of the protein coating which encapsulates the viral DNA or renders RNA ineffective.
The present invention has been found particularly effective in the topical treatment of HSV-1 and HSV-2 strains of herpes simplex virus. The following example is given to aid in understanding the invention, and it is to be understood that the invention is not limited to the particular procedures, proportions or materials of the example.